Diesels have been raced many times, over many years. They have certain advantages, and disadvantages. They are also very capable of running without forced induction.
As gear dawg pointed out, the compression ratio makes everything much more difficult. I would suggest you follow the thread in this forum, it is enlightening.
http://www.eng-tips.com/viewthread.cfm?qid=64541&page=4
On my opinion, maybe one of the largest drawbacks against diesels racing is public perception. To most, diesels are considered workhorses, tough little engines that just keep on running. That's nice if you sell delivery vans. But in the world of adrenaline pumping Formula One, glitz and bling do matter. It's hard to convince any manufacturer to invest .. maybe a billion dollars on an engine program that probably won't see public acceptance. Or racing success, not against the type of engines currently running.